The watch world has several types, including GMT, dual-time, world-time, and UTC watches. Every seasoned watch enthusiast has had to deal with this choice, especially if you’re a frequent traveler. For the most part, these two watch types, GMT and dual-time, have different mechanisms for telling the time. Knowing the main difference between them can help you pick the perfect kind of timepiece to suit your preference. Here’s a guide to help you understand the worlds of GMT and dual-time watches.
What is a GMT Watch?
The best way to approach this GMT vs dual time watches debate is to look at their respective history and backgrounds. GMT is the acronym for Greenwich Mean Time. It’s used to tell the local time in the UK and other countries on the Greenwich Meridian. On the 24-hour scale of international time zones, GMT, defined with a zero, acts as the starting point.
The prime meridian that influences the GMT format is an imaginary line splitting the Earth into two equal parts. Therefore, the timezone for the Western Hemisphere begins with a (-1), while you’ll find world time zones to the East beginning with (+1). This type of watch usually has a 24-hour bezel that syncs with the second time zone. In addition, most true GMT watches have the main hour hand and minute hand operating with the 12-hour format.
The 24-hour hand can be manipulated independently, and like most Rolex watches, they may come in a different color or design.
GMT models that make the 24-hour hand unadjustable can only help a wearer keep track of time and determine if the time is in the AM or PM. To read GMT in the home time zone, you may need to set the GMT bezel at 12:00, so the GMT hand can be consistent with the hour and minute hands.
You can also use the GMT hand to tell the hour in a second-time zone. But depending on how the second time zone is ahead or behind the GMT function, you may have to manipulate the bezel. Popular GMT watch brands include the Omega Sea Master and the Rolex GMT Master, informally known as the Rolex Pepsi because of its blue and red color scheme.
What’s a dual-time watch?
Dual time watches have several features different from GMT and other watch types. Unlike the GMT or the world time watch, a dual time watch can simultaneously display two different time zones without the need for a rotating bezel. The primary time zone sports a larger dial, with the second time zone acting as a sub-dial using the 12-hour time display.
A typical dual time feature you’ll find in dual time model watches is the AM-PM indicator. When monitoring the second time zone on a 12-hour scale, this indicator helps to determine whether it’s day or night. The standard template for a regular traveler using a dual time watch is to set the main dial to display the visiting destination’s time. The sub-dial can then serve as a reminder of their home time zone to avoid losing sight of the time difference. Famous examples of dual-time watches include the Patek Philippe Nautilus Travel Time Chronograph and the Vacheron Constantin Overseas Dual Time 41mm.
Which one is better?
There’s no template or criteria to choose either GMT or dual watches based on performance and design. Instead, a traveler may opt for the dual time function to keep track of time between two specific time zones. Take an individual who resides in New York, United States, and travels to Mexico for periodic meetings, for instance. The dual time watch can help set the time specifically between these two time zones so you can always be in sync. GMT watches can provide the same perk, but you may need a little math and some adjustment to pull through.